U.S. patent number 10,341,516 [Application Number 15/919,643] was granted by the patent office on 2019-07-02 for rotation drive device, image reading device, and image forming apparatus.
This patent grant is currently assigned to RICOH COMPANY, LTD.. The grantee listed for this patent is Takayuki Andoh, Genta Hagiwara, Toshiyuki Horikawa, Daisuke Imaki, Masatoshi Ishida, Tatsuaki Nagano, Satoshi Narai, Yohei Osanai, Kaoru Tada, Yasunobu Youda. Invention is credited to Takayuki Andoh, Genta Hagiwara, Toshiyuki Horikawa, Daisuke Imaki, Masatoshi Ishida, Tatsuaki Nagano, Satoshi Narai, Yohei Osanai, Kaoru Tada, Yasunobu Youda.
United States Patent |
10,341,516 |
Imaki , et al. |
July 2, 2019 |
Rotation drive device, image reading device, and image forming
apparatus
Abstract
A rotation drive device includes a driven rotation member, a
driving rotation member, a rotation relay member, a shaft, and a
holder. The rotation relay member transmits only a unidirectional
rotational driving force from the driving rotation member to the
driven rotation member. The rotation relay member includes a
housing and a cylindrical one-way clutch. A contact portion between
the driving rotation member and the shaft is configured to rotate
the driving rotation member and the shaft to transmit the driving
force to an inner peripheral side of the cylindrical one-way clutch
via the shaft. The driving rotation member includes a boss
projected toward the holder and rotatably held in the holder. A
portion of the shaft to support the driving rotation member and an
inner wall surface of a through hole of the driving rotation member
are shaped to rotate the shaft and the driving rotation member.
together.
Inventors: |
Imaki; Daisuke (Tokyo,
JP), Osanai; Yohei (Kanagawa, JP),
Hagiwara; Genta (Kanagawa, JP), Ishida; Masatoshi
(Kanagawa, JP), Nagano; Tatsuaki (Kanagawa,
JP), Narai; Satoshi (Kanagawa, JP),
Horikawa; Toshiyuki (Kanagawa, JP), Youda;
Yasunobu (Kanagawa, JP), Andoh; Takayuki
(Kanagawa, JP), Tada; Kaoru (Kanagawa,
JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Imaki; Daisuke
Osanai; Yohei
Hagiwara; Genta
Ishida; Masatoshi
Nagano; Tatsuaki
Narai; Satoshi
Horikawa; Toshiyuki
Youda; Yasunobu
Andoh; Takayuki
Tada; Kaoru |
Tokyo
Kanagawa
Kanagawa
Kanagawa
Kanagawa
Kanagawa
Kanagawa
Kanagawa
Kanagawa
Kanagawa |
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A |
JP
JP
JP
JP
JP
JP
JP
JP
JP
JP |
|
|
Assignee: |
RICOH COMPANY, LTD. (Tokyo,
JP)
|
Family
ID: |
63521333 |
Appl.
No.: |
15/919,643 |
Filed: |
March 13, 2018 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20180270375 A1 |
Sep 20, 2018 |
|
Foreign Application Priority Data
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|
|
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Mar 15, 2017 [JP] |
|
|
2017-049884 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H
3/0669 (20130101); B65H 5/06 (20130101); H04N
1/00588 (20130101); B65H 3/0638 (20130101); B65H
3/0684 (20130101); G03G 15/602 (20130101); H04N
1/00602 (20130101); B65H 2404/134 (20130101); B65H
2404/1351 (20130101); B65H 2403/72 (20130101); B65H
2801/06 (20130101); B65H 2403/42 (20130101); G03G
2221/1657 (20130101); B65H 2801/39 (20130101) |
Current International
Class: |
H04N
1/00 (20060101); B65H 5/06 (20060101); B65H
3/06 (20060101); G03G 15/00 (20060101) |
Field of
Search: |
;358/498 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2012-123123 |
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Jun 2012 |
|
JP |
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2013-173581 |
|
Sep 2013 |
|
JP |
|
2014-003421 |
|
Jan 2014 |
|
JP |
|
2016-225918 |
|
Dec 2016 |
|
JP |
|
Primary Examiner: Nguyen; Ngon B
Attorney, Agent or Firm: Harness, Dickey & Pierce,
P.L.C.
Claims
What is claimed is:
1. A rotation drive device comprising: a driven rotation member; a
driving rotation member to receive rotational driving force from a
driving source; a rotation relay member to transmit only a
unidirectional rotational driving force from the rotational driving
force of the driving rotation member to the driven rotation member;
a shaft; and a holder to hold the driving rotation member, wherein
the driven rotation member, the rotation relay member, and the
driving rotation member have through holes, through which the shaft
passes, including center axis lines of the driven rotation member,
the rotation relay member, and the driving rotation member, wherein
the rotation relay member includes: a housing rotatable with the
driven rotation member; and a cylindrical one-way clutch disposed
at an inner peripheral side of the housing, wherein a contact
portion between the driving rotation member and the shaft is
configured to rotate the driving rotation member and the shaft in
conjunction with each other to transmit the rotational driving
force of the driving rotation member to an inner peripheral side of
the cylindrical one-way clutch via the shaft, wherein the driving
rotation member includes a boss that is projected toward the holder
and is rotatably held in a supporting hole of the holder, and
wherein a portion of the shaft to support the driving rotation
member and an inner wall surface of the through hole of the driving
rotation member are shaped to rotate the shaft and the driving
rotation member together.
2. The rotation drive device according to claim 1, wherein an inner
peripheral surface of the supporting hole of the holder and an
outer peripheral surface of the boss of the driving rotation member
are slidable on each other, and wherein each of the holder and the
driving rotation member includes a resin.
3. The rotation drive device according to claim 1, further
comprising a rotation drive transmitting member to transmit the
rotational driving force to the driving rotation member, wherein
the driving rotation member includes a same material as a material
of the rotation drive transmitting member.
4. An image reading device comprising: a loading portion to load a
sheet having an image to be read; a sheet feeding roller to feed
the sheet loaded on the loading portion; a conveying roller to
convey the sheet fed by the sheet feeding roller; an image reader
to read the image of the sheet conveyed by the conveying roller;
and the rotation drive device according to claim 1 to rotate and
drive the sheet feeding roller.
5. An image forming apparatus comprising: a loading portion to load
a sheet having an image to be read; a sheet feeding roller to feed
the sheet loaded on the loading portion; a conveying roller to
convey the sheet fed by the sheet feeding roller; an image reader
to read the image of the sheet conveyed by the conveying roller; an
image forming unit to form an image on a recording medium based on
the image read by the image reader; and the rotation drive device
according to claim 1 to rotate and drive the sheet feeding
roller.
6. An image forming apparatus comprising: a loading portion to load
a recording sheet on which an image is formed; a sheet feeding
roller to feed the recording sheet loaded on the loading portion; a
conveying roller to convey the recording sheet fed by the sheet
feeding roller; an image forming unit to form the image on the
recording sheet conveyed by the conveying roller; and the rotation
drive device according to claim 1 to rotate and drive the sheet
feeding roller.
Description
CROSS-REFERENCE TO RELATED APPLICATION
This patent application is based on and claims priority pursuant to
35 U.S.C. .sctn. 119(a) to Japanese Patent Application No.
2017-049884, filed on Mar. 15, 2017, in the Japan Patent Office,
the entire disclosure of which is hereby incorporated by reference
herein.
BACKGROUND
Technical Field
Aspects of the present disclosure relate to a rotation drive
device, an image reading device, and an image forming
apparatus.
Related Art
A rotation drive device has been known that includes a driven
rotation member, a driving rotation member to receive rotational
driving forces from a driving source, and a rotation relay member
to transmit only a unidirectional rotational driving force of the
rotational driving forces of the driving rotation member to the
driven rotation member.
SUMMARY
In an aspect of the present disclosure, there is provided a
rotation drive device that includes a driven rotation member, a
driving rotation member, a rotation relay member, a shaft, and a
holder. The driving rotation member receives rotational driving
force from a driving source. The rotation relay member transmits
only a unidirectional rotational driving force from the rotational
driving force of the driving rotation member to the driven rotation
member. The holder holds the driving rotation member. The driven
rotation member, the rotation relay member, and the driving
rotation member have through holes including center axis lines of
the driven rotation member, the rotation relay member, and the
driving rotation member. The shaft passes through the through
holes. The rotation relay member includes a housing rotatable with
the driven rotation member and a cylindrical one-way clutch
disposed at an inner peripheral side of the housing. A contact
portion between the driving rotation member and the shaft is
configured to rotate the driving rotation member and the shaft in
conjunction with each other to transmit the rotational driving
force of the driving rotation member to an inner peripheral side of
the cylindrical one-way clutch via the shaft. The driving rotation
member includes a boss that is projected toward the holder and is
rotatably held in a supporting hole of the holder. A portion of the
shaft to support the driving rotation member and an inner wall
surface of the through hole of the driving rotation member are
shaped to rotate the shaft and the driving rotation member
together.
In another aspect of the present disclosure, there is provided an
image reading device that includes a loading portion, a sheet
feeding roller, a conveying roller, an image reader, and the
above-described rotation drive device. The loading portion loads a
sheet having an image to be read. The sheet feeding roller feeds
the sheet loaded on the loading portion. The conveying roller
conveys the sheet fed by the sheet feeding roller. The image reader
reads the image of the sheet conveyed by the conveying roller. The
rotation drive device rotates and drives the sheet feeding
roller.
In still another aspect of the present disclosure, there is
provided an image forming apparatus that includes a loading
portion, a sheet feeding roller, a conveying roller, an image
reader, an image forming unit, and the above-described rotation
drive device. The loading portion loads a sheet having an image to
be read. The sheet feeding roller feeds the sheet loaded on the
loading portion. The conveying roller conveys the sheet fed by the
sheet feeding roller. The image reader reads the image of the sheet
conveyed by the conveying roller. The image forming unit forms an
image on a recording medium based on the image read by the image
reader. The rotation drive device rotates and drives the sheet
feeding roller.
In still yet another aspect of the present disclosure, there is
provided an image forming apparatus that includes a loading
portion, a sheet feeding roller, a conveying roller, an image
forming unit, and the above-described rotation drive device. The
loading portion loads a recording sheet on which an image is
formed. The sheet feeding roller feeds the recording sheet loaded
on the loading portion. The conveying roller conveys the recording
sheet fed by the sheet feeding roller. The image forming unit forms
the image on the recording sheet conveyed by the conveying roller.
The rotation drive device rotates and drives the sheet feeding
roller.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
A more complete appreciation of the disclosure and many of the
attendant advantages and features thereof can be readily obtained
and understood from the following detailed description with
reference to the accompanying drawings, wherein:
FIG. 1 is an explanatory diagram of an exemplary schematic
arrangement in an image forming apparatus according to an
embodiment of the present disclosure;
FIG. 2 is a top view of an image reading device of the image
forming apparatus of FIG. 1;
FIG. 3 is a perspective view of an automatic document feeder (ADF)
of the image reading device of FIG. 2 as viewed from a side of a
special document supply unit;
FIG. 4 is a perspective view of an example of a pickup roller, a
feed roller, and a driving system of the automatic document feeder
(ADF) of the image reading device of FIG. 2;
FIG. 5 is a partial perspective view of the pickup roller, the feed
roller, and the driving system in FIG. 4 as viewed from another
direction;
FIGS. 6A and 6B are an exploded view and an assembly view,
respectively, of a rotation drive mechanism of a pickup roller
according to a comparative example;
FIG. 7 is an exploded view of an example of a rotation drive
mechanism of the pickup roller of the automatic document feeder
(ADF) of FIG. 4;
FIG. 8A is an explanatory view of an one-way clutch when being
locked;
FIG. 8B is an explanatory view of the one-way clutch when
idling;
FIGS. 9A and 9B are assembly views of the rotation drive mechanism
of the pickup roller of the automatic document feeder (ADF) of FIG.
4; and
FIG. 10 is a partial perspective view of a supporting member of a
shaft at one end of the pickup roller of the rotation drive
mechanism after the automatic document feeder (ADF) of FIG. 4.
The accompanying drawings are intended to depict embodiments of the
present disclosure and should not be interpreted to limit the scope
thereof. The accompanying drawings are not to be considered as
drawn to scale unless explicitly noted.
DETAILED DESCRIPTION
In describing embodiments illustrated in the drawings, specific
terminology is employed for the sake of clarity. However, the
disclosure of this patent specification is not intended to be
limited to the specific terminology so selected and it is to be
understood that each specific element includes all technical
equivalents that operate in a similar manner and achieve similar
results. Although the embodiments are described with technical
limitations with reference to the attached drawings, such
description is not intended to limit the scope of the disclosure
and all of the components or elements described in the embodiments
of this disclosure are not necessarily indispensable. As used
herein, the singular forms "a", "an" and "the" are intended to
include the plural forms as well, unless the context clearly
indicates otherwise.
Referring now to the drawings, embodiments of the present
disclosure are described below. In the drawings for explaining the
following embodiments, the same reference codes are allocated to
elements (members or components) having the same function or shape
and redundant descriptions thereof are omitted below.
An embodiment is described below referring to the drawings. FIG. 1
is an explanatory diagram of an exemplary schematic arrangement in
an image forming apparatus 1 according to the present embodiment.
As illustrated in FIG. 1, the image forming apparatus 1 according
to the present embodiment is an exemplary copying machine including
an apparatus body 10 and an image reading device 20 to read an
image of a document. The apparatus body 10 includes a sheet
container 11 as a recording medium container to house sheets as a
recording medium on which an image is formed and an image forming
device (image formation unit) 12 as an image forming unit. The
image reading device 20 includes an image reading unit 21 as an
image reader and an automatic document feeder (referred to as
"ADF") 22 as a document supplying device. The document includes an
image read by the image reading unit 21.
The image forming device 12 includes, for example, an exposure unit
as exposure means, a plurality of photoconductor drums, a
developing device using toners of four colors, i.e., cyan (C),
magenta (M), yellow (Y), and black (K), a transfer belt as an
intermediate transfer body, a secondary transfer unit, and a fixing
unit. The image forming device 12 forms an image, for example, as
follows, based on a read image of the document read by the image
reading device 20 or print data transmitted from an external device
such as a personal computer (PC). The image forming device 12
exposes the photoconductor drum of each color by the exposure unit
based on the print data to form an electrostatic latent image on
each photoconductor drum and supplies the toner on the latent image
on each photoconductor drum by each color developing unit of the
developing device to develop the image. The image forming device 12
primarily transfers the toner image on each photoconductor drum to
the transfer belt and secondarily transfers the toner image on the
sheet as the recording medium by the secondary transfer unit in an
overlapped manner. After that, the toner images on the sheet are
heated and pressed, and fixed by the fixing unit to form a color
image.
The image reading device 20 can be operated while switching a DF
scanner mode (fed document reading mode) and a flat bed scanner
mode (loaded document reading mode). The DF scanner mode is a mode
in which an image of a document is read during automatic conveyance
when the document is conveyed by the ADF 22. The flat bed scanner
mode (hereinafter referred to as "FBS mode") is a mode in which an
image of a document loaded on a flat bed contact glass 215 is
read.
In the FBS mode, the image reading unit 21 can read a document
image by irradiating an image surface of the document (for example,
individual document sheet, heavy paper, book, and card) on the flat
bed contact glass 215 with light and converting reflection light
from the image surface into an image signal. Here, the "individual
document sheet" indicates, for example, a document including one
sheet with a fixed size such as A3, A4, and A5 (hereinafter
referred to as "document sheet").
In the DF scanner mode, the ADF 22 separates a single document
sheet from a bundle of document sheets loaded on a document tray
(multi-tray) 221, which is a sheet loading member (sheet loader),
by a pickup roller 222 as a sheet feeding roller and feeds the
separated document sheet. The document tray 221 is disposed above a
discharging tray 226 as a sheet ejecting unit to eject the document
which is a sheet to be conveyed. Furthermore, the document tray 221
turns around a turn supporting member of the ADF body by a user's
operation and can be in a closed state in which the document tray
221 is closed to cover the discharging tray 226 and an opened state
in which the document tray 221 is opened to open the discharging
tray 226.
The document sheet fed from the document tray 221 is brought in a
document conveyance passage 228 as a sheet conveying passage by a
feed roller 223 as a sheet conveying roller. In addition, the
document sheet is conveyed along the document conveyance passage
228 by conveying rollers 224 and 225. During the conveyance, the
document sheet partially faces to a DF contact glass (slit glass)
216 on the top surface side of the image reading unit 21 from the
front end portion in the conveyance direction in sequence. That is,
the image reading device 20 sequentially reads the image on the
document sheet conveyed by the ADF 22, on the DF contact glass 216
of the image reading unit 21 so as to serve as a DF scanner.
Between the flat bed contact glass 215 and the DF contact glass
216, a relay supporting member is disposed to support and relay the
flat bed contact glass 215 and the DF contact glass 216. A
back-side reader 219 to read the back side of the document sheet is
disposed opposite to the DF contact glass 216 via the document
conveyance passage 228.
The ADF 22 is attached to a rear portion of the top surface of the
apparatus body 10 (portion on rear surface side in FIG. 1) via an
opening/closing mechanism such as a hinge. The ADF 22 can be
positioned at an opening position where the flat bed contact glass
215 is opened relative to the apparatus body 10 and a closing
position where the document can be pressed against the flat bed
contact glass 215.
FIG. 2 is a top view of the image reading device 20 according to
the present embodiment. To the document tray 221, a right-and-left
pair of movable side guide plates 229 which positions a document
sheet S set on a document loader 221a in the width direction
perpendicular to a document feeding direction (sheet conveyance
direction) is attached. The side guide plates 229 are formed to
relatively move close to or apart from each other so that the
center of the document tray 221 in the width direction coincides
with the center of the document sheet S in the width direction. The
side guide plates 229 may be arranged in a state where one end of
the document sheet S is brought into contact with one end of the
document tray 221 and the other end can be moved.
The ADF 22 is covered with a cover 230. At least an upper side of
the cover 230 can be opened and closed. In the cover 230, a sheet
feed opening 230a is formed above a place near the sheet-feeding
end of the document tray 221 so that the leading end of the
document sheet S enters the cover 230. The cover 230 covers above
the leading end portion of the document tray 221 in the conveyance
direction so that the leading end portion of the document tray 221
is housed to the inner side of the sheet feed opening 230a.
Furthermore, in the ADF 22, a principal guide portion forming a
conveyance path of the document conveyance passage 228 from the
sheet feed opening 230a to a sheet ejection opening is formed by a
rib on the cover 230 and the like.
As illustrated in FIG. 1, when the document such as the document
sheet S to be read is loaded in a case where the image reading
device 20 functions as a flat bed scanner (FBS), the flat bed
contact glass 215 faces an image surface of the document. In a case
where the image reading device 20 functions as a DF scanner, the DF
contact glass 216 faces an image surface of the following special
document. That is, the DF contact glass 216 faces the image surface
of the document sheet S passing through a predetermined reading
position of the document conveyance passage 228 or the image
surface of the special document, which is not flexible, such as a
small card-shaped document and a thick document to be described
later. In addition, the DF contact glass 216 is inclined to form a
previously set inclination angle with respect to the flat bed
contact glass 215.
The image reading unit 21 includes a first reading unit including a
carriage 211 and an integral optical scanning unit 212 as an image
reading element for both the FBS and a guide rail (also referred to
as "guide rod") 214 extending along the horizontal direction in
FIG. 1. The carriage 211 of the first reading unit includes, for
example, a bracket which holds the integral optical scanning unit
212 and compression coil springs as a plurality of elastic members.
The compression coil spring is incorporated between the integral
optical scanning unit 212 and the bracket of the carriage 211 in a
compressed state. Furthermore, under the carriage 211, a detection
target 213 to be detected by home position sensors 217 and 218
including a reflection or transmission type optical sensor and the
like. The position detected by the home position sensor 217 of the
first reading unit is a home position in the DF scanner mode, and
the position detected by the home position sensor 218 is a home
position in the FBS mode.
For example, the integral optical scanning unit 212 is formed as a
contact image sensor to make a mold frame hold an unmagnification
imaging element roof mirror lens array, an unmagnification image
sensor, an illumination light source, and the like. The integral
optical scanning unit 212 can line-scan an image with high
resolution in the main scanning direction and has a large depth of
focus with which the integral optical scanning unit 212 can read an
image of a document such as a book. The main scanning direction is
a direction parallel to both of the top surface of the flat bed
contact glass 215 and the top surface of the DF contact glass 216.
The structure of the integral optical scanning unit 212 is not
limited to a specific system as long as the integral optical
scanning unit 212 can use both the DF scanner and the flat bed
scanner.
Above the integral optical scanning unit 212, a rectangular annular
upper slider which smoothly slides and moves along the sub-scanning
direction while having contact with the lower surface of at least
one of the flat bed contact glass 215 and the DF contact glass 216
is attached. The upper sliders may be projections which extend
along the longitudinal direction or the short direction of the
integral optical scanning unit 212 and take apart from each other
along a direction perpendicular to the extending direction.
Furthermore, the upper slider may include a plurality of
hemispherical projections. In either case, it is preferable that
the upper slider include a material which has a low friction
coefficient, excellent slidability and movability, and no
lubrication relative to the lower surfaces of the flat bed contact
glass 215 and the DF contact glass 216, or other guide surface
instead of the lower surfaces.
The integral optical scanning unit 212 is guided by a guide rail
214 arranged below the bracket of the carriage 211 to be movable in
the sub-scanning direction (direction of arrow A in FIG. 1).
According to the position in the sub-scanning direction, the upper
part of the integral optical scanning unit 212 slidably has contact
with one of or both of the flat bed contact glass 215 and the DF
contact glass 216. With this structure, although the first reading
unit is movable along the guide rail 214, an inclination relative
to the axis of the guide rail 214 is regulated.
By line-scanning the image surface of the document on the flat bed
contact glass 215 in the main scanning direction and moving along
the sub-scanning direction, the first reading unit can read the
image of the document. By line-scanning the image of the conveyed
document passing through the upper side of the DF contact glass 216
in the main scanning direction, the first reading unit can read the
image of the document.
The image reading unit 21 includes an endless loop-shaped timing
belt. At one position in the circumferential direction of the
timing belt, the carriage 211 of the first reading unit is secured.
The image reading unit 21 includes, e.g., a plurality of timing
pulleys and a motor to rotate and drive any one of the timing
pulleys. Around the plurality of timing pulleys, the timing belt is
stretched without loosing
In a case where the image reading device 20 performs a reading
operation in the FBS mode, the first reading unit moves to the
right side in FIG. 1 while moving from the FSB home position
detected by the home position sensor 218 to one side in the
sub-scanning direction. For each very short moving distance, the
integral optical scanning unit 212 performs line scanning to read
an image of the surface (lower surface) of the document loaded on
the flat bed contact glass 215. When the reading operation ends,
the first reading unit returns to the FSB home position again.
In a case where the reading operation in the DF scanner mode is
performed, the first reading unit moves from the DF home position
detected by the home position sensor 217 to the lower side of the
DF contact glass 216. That is, the first reading unit moves a
previously set distance from the DF home position to the opposite
side in the sub-scanning direction and stops below the DF contact
glass 216, and then reads the image on the surface of the document
passing through the DF contact glass 216.
In this way, the first reading unit can move in the sub-scanning
direction to be positioned at both the position below the flat bed
contact glass 215 and the position below the DF contact glass 216.
According to the position in the sub-scanning direction, the
attitude of the integral optical scanning unit 212 is changed
between a horizontal first reading attitude and a second reading
attitude. At the first reading attitude, the integral optical
scanning unit 212 can read an image through the flat bed contact
glass 215, and at the second reading attitude, the integral optical
scanning unit 212 is inclined to be capable of reading an image
through the DF contact glass 216.
As described above, the ADF 22 includes the document tray 221 and
the document conveyance passage 228 through which the document
sheet S is conveyed in a state where the image of the document
sheet S can be read. In addition, the ADF 22 includes the
discharging tray 226 as an ejected sheet loading unit where the
document sheet S of which the image has been read or the special
document such as a card C to be described later is ejected and
stacked. Immediately below the document tray 221, a space is
provided where a user can take the sheet on the discharging tray
226. For miniaturization, the document tray 221 and the discharging
tray 226 are vertically stacked in a state where at least a part of
the trays are separated from each other.
FIG. 3 is a perspective view of the automatic document feeder (ADF)
22 according to the present embodiment as viewed from a side of a
special document supply unit 231. The special document supply unit
231 is a document supply unit which supplies the special document
such as a small card-shaped document (hereinafter referred to as
"card") C and a thick document. The special document such as the
card C and the thick document is a document including an image to
be read. The automatic document feeder (ADF) 22 according to the
present embodiment can eject the special document such as the card
C, supplied and conveyed from the special document supply unit 231,
on the discharging tray 226.
Here, the card C may be a thick resin card such as a cash card of a
bank and the like and various credit cards and a card with a
standard fixed size including a resin and the like (may be heavy
paper), for example, a driver's license, an identification card (ID
card), and a traffic card. The "small size" indicates, for example,
a size smaller than a post card, and may be a size of a card
identical to or substantially same as any one of ID-1, ID-2, and
ID-3 of ISO/IEC7810 which is an international standard that defines
the shape of the ID card.
As illustrated in FIGS. 3 and 2 described above, the special
document supply unit 231 includes the conveying roller 224, a
special document supply port 232, a special document supply tray
(bypass tray) 227, and a special document conveyance passage 233.
Here, the conveying roller 224 functions as a pair of pickup
rollers as sheet feeding rollers to feed the special document such
as the card C.
As illustrated in FIG. 2, the special document supply tray 227 is
normally closed and forms a part of a side surface of the cover
230, and can turn to open the special document supply port 232.
Furthermore, in the closed state, the special document supply tray
227 forms a part of a conveyance guide for the document sheet S
which is a normal document.
The conveying roller (pickup roller) 224 takes and feeds the
special document such as the card C including the image to be read
which has been set on the special document supply tray 227 and
supplies the special document to the special document conveyance
passage 233.
The special document conveyance passage 233 is a downwardly
inclined path from the special document supply port 232 to the DF
contact glass 216 without being curved and joins to the document
conveyance passage 228 on the upstream side of the DF contact glass
216. At this time, the special document conveyance passage 233 is
positioned on the same plane as the DF contact glass 216 along an
inclination angle of the DF contact glass 216 in a range from the
special document supply port 232 to the DF contact glass 216,
according to the downward inclination of the DF contact glass
216.
The ADF 22 according to the present embodiment is miniaturized and
shortens the reading time. Furthermore, the ADF 22 according to the
present embodiment can read the image of the special document such
as a small and thick resin card and can cope with diversification
in document reading.
Next, a rotation drive mechanism as a rotation drive device of the
automatic document feeder (ADF) 22 according to the present
embodiment is described. FIG. 4 is a perspective view of an example
of the pickup roller 222, the feed roller 223, and a driving system
of the ADF 22 of the image reading device according to the present
embodiment. FIG. 5 is a partial perspective view of the pickup
roller 222, the feed roller 223, and the driving system in FIG. 4
as viewed from another direction. FIGS. 6A and 6B are partial
perspective views of a supporting member at one end of a shaft 270
of the pickup roller 222 of the ADF 22 according to the present
embodiment.
As described above, the pickup roller 222 is a roller which
separates the document sheets S one by one from a bundle of
document sheets loaded on the document tray 221 and feeds the
separated document sheet S. A rotation drive mechanism 240 as a
rotation drive device to rotate and drive the pickup roller 222
includes the pickup roller 222 as a driven rotation member, a gear
250 as a driving rotation member, and a rotation relay member
260.
The gear 250 receives rotational driving force from a driving
source such as a motor. In the example in FIG. 4, the rotational
driving force is transmitted from an output gear 310 mounted on a
driving shaft 300 to transmit the rotational driving force from the
motor to the feed roller 223 to the gear 250 via relay gears 320,
330, and 340 as rotation drive transmitting members.
The rotation relay member 260 transmits only a rotational driving
force in one rotation direction, which is a predetermined rotation
direction, of the rotational driving force of the gear 250 to the
pickup roller 222. In the one rotation direction, the document
sheet S is fed. The pickup roller 222 which has received the
rotational driving force in the one rotation direction which is the
predetermined rotation direction can feed the document sheet S
toward the feed roller 223. Even when the rotational driving force
in the direction reverse to the feeding direction of the document
sheet S is transmitted to the gear 250 for some cause, the
rotational driving force of the gear 250 is not transmitted to the
pickup roller 222. Therefore, this reduces generation of errors in
feeding the document sheet S.
The gear 250 of the rotation drive mechanism 240 as the rotation
drive device according to the present embodiment may include a
material same as materials of the output gear 310 and the relay
gears 320, 330, and 340 to transmit the rotational driving force to
the gear 250. In this case, occurrence of scrap of one member of
the gear 250 and the output gear 310 and the relay gears 320, 330,
and 340 and abnormal noise due to a difference in materials of both
members can be suppressed. The pickup roller 222 may be driven by a
driving source such as another motor different from the driving
source of the feed roller 223 such as the motor.
The rotation drive mechanism 240 is assembled in a state where the
shaft 270 sequentially passes through holes of the pickup roller
222, the rotation relay member 260, and the gear 250. The through
holes contain the respective center axis lines. The rotation drive
mechanism 240 as the rotation drive device according to the present
embodiment is configured as described later to improve an
assembling performance at the time when the shaft 270 is inserted
through the through holes to assemble the rotation drive mechanism
240.
FIGS. 6A and 6B are an exploded view and an assembly view of a
rotation drive mechanism as a rotation drive device of a pickup
roller 910 according to a comparative example. The rotation drive
mechanism according to the comparative example in FIGS. 6A and 6B
includes a gear-coupled-type clutch (mechanical clutch) 900 as a
rotation relay member. The clutch 900 includes a ratchet gear 911
on the side surface of the pickup roller 910 in the circumferential
direction and a rotation relay member 920 having a ratchet gear 921
to be engaged with the ratchet gear 911 on the output-side side
surface in the circumferential direction. In the clutch 900, by
engaging the two ratchet gears, only the unidirectional rotational
driving force of the rotational driving force transmitted from a
driving rotation member 930 to the input side of the rotation relay
member 920 is transmitted to the pickup roller 910.
However, the rotation drive mechanism according to the comparative
example should be assembled by subsequently inserting a shaft 940
through respective through holes of the driving rotation member
930, the rotation relay member, and the pickup roller 910 and
attaching the assembly to holders 950 and 960. Accordingly, an
assembling performance is low.
Therefore, regarding the rotation drive mechanism 240 of the pickup
roller 222 according to the present embodiment, it is intended to
improve the assembling performance by reducing the number of
members through which the shaft is inserted.
FIG. 7 is an exploded view of an example of the rotation drive
mechanism 240 as the rotation drive device of the pickup roller 222
of the ADF 22 according to the present embodiment. In the rotation
drive mechanism 240 as the rotation drive device according to the
present embodiment, the rotation relay member 260 includes a
housing 261 and a cylindrical one-way clutch 262 press-fitted in
the housing 261. The housing 261 includes a resin with high
slidability (for example, polyacetal resin (polyoxyrnethylene (POM)
resin)) to be integrally rotated with the gear 250. A boss 261a
projected toward the pickup roller 222 of the housing 261 of the
rotation relay member 260 is secured into a recess 222b in the side
surface of the pickup roller 222 on the side of the gear 250.
At an end opposite to the end of the pickup roller 222 where the
housing 261 of the rotation relay member 260 is secured, a claw
222c is fitted into and engaged with a recess (concave) 270b of the
shaft 270 at the time of assembly. Here, the pickup roller 222 can
include a synthetic component of ethylene propylene diene rubber
(EPDM rubber) and a resin with high slidability (for example,
polyacetal resin (POM resin)). The housing 261 of the rotation
relay member 260 may be integrally formed with the pickup roller
222.
As illustrated in FIG. 7, a leading end 270a of the shaft 270 on
the side of the gear to be inserted from a through hole 280a of a
holder 280 to the gear 250 in a direction indicated by an arrow
(that is, a portion corresponding to a through hole 250a of the
gear 250 after assembly) is formed to have a cross section having a
partially lacked circular shape of which a part of the
circumference is lacked (D-cut shape). In addition, the through
hole 250a of the gear 250 is formed to have a cross section having
a partially lacked circular shape (D-cut shape) to be engaged with
the partially lacked circular shaped leading end 270a of the shaft
270. In this way, by forming the partially lacked circular shaped
cross sections of the leading end 270a of the shaft 270 on the side
of the gear and the through hole 250a of the gear 250 to be engaged
with each other, the shaft 270 and the gear 250 are integrally
rotated.
To prevent the pickup roller 222 from being extracted, the recess
(concave) 270b is formed in the shaft 270, and the claw 222c of the
pickup roller 222 is fitted into and engaged with the recess
(concave) 270b. At the time of assembly, the elastic claw 222c of
the pickup roller 222 is fitted into the recess (concave) 270b of
the shaft 270 so that the pickup roller 222 is not extracted.
The gear 250 includes a boss 251 projected toward a holder 290 so
as to be rotatably held in a supporting hole 290a in the holder
290. Here, when the gear 250 rotates, the outer peripheral surface
of the boss 251 of the gear 250 slides with respect to the inner
peripheral surface of the supporting hole 290a of the holder 290.
To suppress the occurrence of the scrap and the abnormal noise of
the gear 250 and the holder 290 due to the sliding movement, the
gear 250 and the holder 290 may include a resin. Without forming
the entire gear 250 and the entire holder 290 with a resin, it is
possible that at least outer peripheral portion of the boss 251 of
the gear 250 includes a resin and at least an inner peripheral
portion of the supporting hole 290a of the holder 290 includes a
resin. By forming the components with a resin in this way, the
resins slide with each other. Therefore, the occurrence of the
scrap and abnormal noise is suppressed, and high durability can be
obtained.
Here, the holders 280 and 290 can include, for example, resin
materials having high rigidity (for example, ABS resin which is
copolymer synthetic resin of acrylonitrile, butadiene, and
styrene). Furthermore, the gear 250 including the boss 251 can
include, for example, a material with high slidability (for
example, polyacetal resin (POM resin)).
FIG. 8A is an explanatory view of an one-way clutch 262 when being
locked, and FIG. 8B is an explanatory view of the one-way clutch
when idling. The one-way clutch 262 includes a cylindrical clutch
housing 262a having a plurality of cam-shaped recesses on an inner
peripheral surface in the circumferential direction and a ball 262c
which is coupled to springs 262b arranged in the respective
recesses of the clutch housing 262a. The shaft 270 which rotates in
conjunction with the gear 250 passes through a through hole 260a
containing the center axis line of the one-way clutch 262. The
shaft 270 is inserted through the through hole 260a of the one-way
clutch 262 while rotating the shaft 270 in an idling direction.
Here, for example, the clutch housing 262a can include a resin with
high slidability (for example, polyacetal resin (POM resin)), and
the ball 262c can include metal. In addition, the ball 262c may be
a roller.
When the one-way clutch 262 is locked (at the time of feeding
document sheet) as in FIG. 8A, the shaft 270 which rotates in
conjunction with the gear 250 in one predetermined rotation
direction is engaged with the clutch housing 262a via the ball
262c. In this state, torque of the shaft 270 is transmitted to the
clutch housing 262a via the ball 262c, and the clutch housing 262a
rotates in a direction of an arrow in FIG. 8A. With this rotation,
the pickup roller 222 is rotated and driven together with the
housing 261 of the rotation relay member 260.
On the other hand, when the one-way clutch 262 idles as in FIG. 8B,
even when the shaft 270 rotates in the direction reverse to the
predetermined direction, the spring 262b contracts, and the ball
262c moves toward the clutch housing 262a. Therefore, the torque of
the shaft 270 is not transmitted to the clutch housing 262a.
Accordingly, the shaft 270 idles without rotating the clutch
housing 262a, the housing 261 of the rotation relay member 260, and
the pickup roller 222.
FIGS. 9A and 9B are assembly views of the rotation drive mechanism
240 of the pickup roller 222 of the ADF 22 according to the present
embodiment. FIG. 10 is a partial perspective view of a supporting
member of the shaft 270 of the assembled rotation drive mechanism
240 at one end (side of gear). The pickup roller 222, the rotation
relay member 260, and the gear 250 are rotatably supported by the
holders 280 and 290 with the shaft 270 passing through the through
holes 222a, 260a, and 250a of the respective members in this order.
As described above, the housing 261 of the rotation relay member
260 is rotatable together with the pickup roller 222, and the
cylindrical one-way clutch 262 is fitted into the housing 261.
Therefore, the pickup roller 222 and the rotation relay member 260
are formed as a member having an integrated structure. The rotation
drive mechanism 240 can be assembled by inserting the shaft 270
through the through holes 222a and 260a of the member having the
integrated structure and the through hole 250a of the gear 250.
Since the rotation drive mechanism 240 can be assembled by
inserting the shaft 270 through the through holes 222a and 260a of
the two members, the assembling performance of the rotation drive
mechanism 240 can be improved.
In the embodiment, a case where the sheet to be fed and conveyed by
the pickup roller is the document of which the image is read has
been described. However, the sheet to be conveyed may be a sheet
other than the document. For example, the present invention can be
applied to the rotation drive mechanism of the pickup roller to
feed the recording medium such as a sheet-like recording sheet
contained in the sheet container 11. In the embodiment, an
exemplary structure in which the through hole 222a is formed in the
pickup roller 222 has been described. However, it is possible that
the pickup roller 222 does not have a through hole. In this case,
for example, it is preferable that a boss be formed in the pickup
roller 222 on the side of the holder 280 and the boss of the pickup
roller 222 be rotatably held by the holder 280.
An example has been described above, and a specific effect is
obtained for each of the following modes.
Aspect A
A rotation drive device, such as the rotation drive mechanism 240,
includes a driven rotation member, such as the pickup roller 222, a
rotation member, such as the driving gear 250, to receive
rotational driving force from a driving source, such as a motor,
and a rotation relay member, such as the rotation relay member 260,
to transmit only a unidirectional.
rotational driving force from the rotational driving force of the
driving rotation member to the driven rotation member. The rotation
relay member and the driving rotation member have through holes,
such as the through holes 250a and 260a, respectively, including
center axis lines, through which a shaft, such as the shaft 270,
passes. The through holes of the rotation relay member and the
driving rotation member, respectively, include center axis lines of
the rotation relay member and the driving rotation member. The
rotation relay member includes a housing, such as the housing 261,
rotatable together with the driven rotation member and a
cylindrical one-way clutch, such as the cylindrical one-way clutch
262, disposed at an inner peripheral side of the housing. A contact
portion between the driving rotation member and the shaft is formed
to rotate the driving rotation member and the shaft in conjunction
with each other so that the rotational driving force of the driving
rotation member is transmitted to an inner peripheral side of the
one-way clutch via the shaft. The driving rotation member, such as
the driving gear 250, includes a boss, such as the boss 251, which
is projected toward a holder, such as the holder 290, to hold the
driving rotation member and is rotatably held in a supporting hole,
such as the supporting hole 290a, formed in the holder. A portion
of the shaft, such as the leading end 270a of the shaft 270, to
support the driving rotation member and an inner wall surface of
the through hole of the driving rotation member are formed so that
the shaft and the driving rotation member are rotatable together.
According to aspect A, as described in the above-described
embodiment, since the rotation relay member and the driven rotation
member are integrally formed, it is preferable that the shaft is
inserted toward the through hole of the integrally formed rotation
relay member at the time of assembly. Therefore, since the shaft
can be more easily inserted through the integrated member at the
time of assembly than a case where the shaft is inserted through
two members separated from each other, the assembling performance
of the rotation drive device can be improved. In addition, before
the shaft is inserted through the integrally formed member and the
driving rotation member, the boss of the driving rotation member
can be rotatably held in the supporting hole formed in the holder
in advance. Therefore, the assembling performance is further
improved.
Aspect B
In the above-described aspect A, an inner peripheral surface of the
supporting hole, such as the supporting hole 290a, in the holder,
such as the holder 290, and an outer peripheral surface of the
boss, such as the boss 251, of the driving rotation member, such as
the gear 250, are slidable on each other, and the holder and the
driving rotation member include a resin. Accordingly, as described
in the above-described embodiment, when the driving rotation member
rotates, the resin of the driving rotation member and the resin of
the holder are slid on each other. Therefore, occurrence of a scrap
of one member and abnormal noise due to a difference between
materials of both members can be suppressed.
Aspect C
In the above-described aspects A or B, the driving rotation member,
such as the gear 250, includes the same material as materials of
the rotation drive transmitting members, such as the output gear
310 and the relay gears 320, 330, and 340, to transmit the
rotational driving force to the driving rotation member.
Accordingly, as described in the above-described embodiment, the
occurrence of the scrap of one of the rotation member and the
rotation drive transmitting member and the abnormal noise due to
the difference between the materials of both members can be
suppressed.
Aspect D
An image reading device, such as the image reading device 20,
includes a loading portion, such as the document tray 221, to load
a sheet, such as the document sheet S, having an image to be read,
a sheet feeding roller, such as the pickup roller 222, to feed the
sheet loaded on the loading portion, a conveying roller, such as
the feed roller 223, to convey the sheet fed by the sheet feeding
roller, and an image reader, such as the image reading unit 21, to
read the image of the sheet conveyed by the conveying roller. The
image reading device includes the rotation drive device in any one
of the above-described aspects A to C as a rotation drive device to
rotate and drive the sheet feeding roller. According to Aspect D,
as described in the above-described embodiment, an assembling
performance of the rotation drive device which transmits only a
unidirectional rotational driving force from the rotational driving
force of the driving rotation member in the image reading device to
the sheet feeding roller to rotate and drive the sheet feeding
roller can be improved.
Aspect E
An image forming apparatus, such as the image forming apparatus 1,
includes a loading portion, such as the document tray 221, to load
a sheet, such as the document sheet S, having an image to be read,
a sheet feeding roller, such as the pickup roller 222, to feed the
sheet loaded on the loading portion, a conveying roller, such as
the feed roller 223, to convey the sheet fed by the sheet feeding
roller, an image reader, such as the image reading unit 21, to read
the image of the sheet conveyed by the conveying roller, and an
image forming unit, such as the image forming device 12, to form an
image on a recording medium, such as a sheet, based on the image
read by the image reader. The image forming apparatus includes the
rotation drive device in any one of the above-described aspects A
to C as a rotation drive device to rotate and drive the sheet
feeding roller. According to Aspect E, as described in the
above-described embodiment, an assembling performance of the
rotation drive device which transmits only a unidirectional
rotational driving force from the rotational driving force of the
driving rotation member in the image reading device of the image
forming apparatus to the sheet feeding roller to rotate and drive
the sheet feeding roller to rotate and drive the sheet feeding
roller can be improved.
Aspect F
An image forming apparatus, such as the image forming apparatus 1,
includes a loading portion, such as a paper feeding tray, to load a
recording medium, such as a recording sheet of paper, on which an
image is formed, a sheet feeding roller, such as a pickup roller,
to feed the recording medium loaded on the loading portion, a
conveying roller to convey the recording medium fed by the sheet
feeding roller, and an image forming unit, such as an image forming
device 12, to form an image on the recording medium conveyed by the
conveying roller. The image forming apparatus includes the rotation
drive device of any one of the above-described aspects A to C as a
rotation drive device to rotate and drive the sheet feeding roller.
With this structure, as described in the above-described
embodiment, an assembling performance of the rotation drive device
which transmits unidirectional rotational driving force of
rotational driving force of a driving rotation member in the image
forming apparatus to the sheet feeding roller to rotate and drive
the sheet feeding roller can be improved.
Numerous additional modifications and variations are possible in
light of the above teachings. It is therefore to be understood
that, within the scope of the above teachings, embodiments of the
present disclosure may be practiced otherwise than as specifically
described herein. With some embodiments having thus been described,
it will be obvious that the same may be varied in many ways. Such
variations are not to be regarded as a departure from the scope of
the present disclosure and appended claims, and all such
modifications are intended to be included within the scope of the
present disclosure and appended claims.
* * * * *